To check fluid levels, remove the maintenance panel:
1. Open the hood.
2. Pull the maintenance panel upward to release the clips that hold it in place.
CAUTION: The maintenance panel protects the front trunk from water. When re-attaching, make sure it is fully seated.
Checking Battery Coolant
Your Battery coolant should not need to be replaced for the life of your vehicle under most circumstances. However, if the quantity of fluid in the cooling system drops below the recommended level, the instrument panel displays a warning message. Stop driving Model S as soon as safety permits and contact Tesla.
Fluid Level Check
DO NOT REMOVE THE FILLER CAP AND DO NOT ADD FLUID. Doing so can result in damage not covered by the warranty.
Do Not Top Up Battery Coolant
WARNING: Battery coolant can be hazardous and can irritate eyes and skin. Under no circumstances should you remove the filler cap and/or add coolant. If the instrument panel warns you that the fluid level is low, contact Tesla immediately.
To maximize the performance and life of the Battery, the cooling system uses a specific mixture of G-48 ethylene- glycol coolant (HOAT). Contact Tesla for more specific information about the coolant.